The invention relates to compact circuit packages for electrical components, including high power applications.
A circuit package typically includes an electrically insulating thermally conductive ceramic substrate bonded on a base plate or heat sink. Lead frames and electrical components are bonded on the ceramic substrate, and a housing covers the circuit components and substrate. A first coating material, such as a soft silicon sealer, covers the circuit components in the housing, and a second coating, such as hardened epoxy, covers the soft silicon.
During current flow through the lead frames and electrical components, the soft silicon is heated and thermally expands, which may tend to push the ceramic substrate away from the housing, and apply undesirable forces against internal components. The present invention addresses and solves this problem.